Priorities USA was the top super PAC behind President Barack Obama's re-election bid last year and is setting up to back Clinton if she runs in 2016.

Sources told Buzzfeed Mantz would raise cash for a "pro-Clinton paid media effort" led by veteran operatives Jim Messina and John Podesta and that he has "already been making calls to other fundraisers and consultants in Washington to inform them of the new arrangement."

A spokesperson for Priorities USA confirmed the PAC was in talks with Mantz.